Method of manufacturing optical fiber

Abstract

A coating is applied on an optical fiber drawn from a melted tip of an optical-fiber preform. A glass spin is applied to a coated optical fiber by gripping the coated optical fiber with at least a pair of spinning applying rollers arranged in different levels with parallel rotation axes, rotating the spinning applying rollers so that the coated optical fiber is guided in a predetermined direction, and alternately shifting the spinning applying rollers in opposite directions along the rotation axes. The glass spin is applied to the coated optical fiber in a state in which each of the rotation axes is tilted at a predetermined angle from a plane perpendicular to the first direction.

1 . A method of manufacturing an optical fiber, comprising:
 drawing an optical fiber from a melted tip of an optical-fiber preform;   forming a coated optical fiber by applying a coating on an outer circumference of the optical fiber drawn at the drawing; and   applying a glass spin to the coated optical fiber by causing the coated optical fiber to make contact with a surface of an oscillating roller, rotating the oscillating roller around its rotation axis so that the coated optical fiber is guided in a first direction, and oscillating the rotation axis of the oscillating roller periodically centering around a second direction tilted at a predetermined angle from a plane perpendicular to the first direction.   
     
     
         2 . The method according to  claim 1 , further comprising adjusting the predetermined angle depending on a mechanical twist of the coated optical fiber. 
     
     
         3 . The method according to  claim 1 , further comprising correcting a mechanical twist on the coated optical fiber, the correcting including
 causing the optical fiber applied with the glass spin to make contact with a surface of a correction roller,   rotating the correction roller around its rotation axis so that the optical fiber applied with the glass spin is guided in a third direction, and   applying another glass spin in a direction opposite to a direction of the mechanical twist of the optical fiber applied with the glass spin by tilting the rotation axis of the correction roller at a predetermined angle from a plane perpendicular to the third direction.   
     
     
         4 . The method according to  claim 2 , further comprising correcting the mechanical twist on the coated optical fiber, the correcting including
 causing the optical fiber applied with the glass spin to make contact with a surface of a correction roller,   rotating the correction roller around its rotation axis so that optical fiber applied with the glass spin is guided in a third direction, and   applying another glass spin in a direction opposite to a direction of the mechanical twist of the optical fiber applied with the glass spin by tilting the rotation axis of the correction roller at a predetermined angle from a plane perpendicular to the third direction.